Diet is one of the least understood and complied with aspects of treatment in patients with CF. In one assessment study of adherence to dietary recommendations, Gudas found that 40% of children and 47% of parents disagreed with their physician on whether diet was a formal recommendation. Henley reported many misconceptions of symptoms and treatment of malabsorption and diet. Any education program targeting dietary treatment in children with CF needs to address two knowledge and/or skill components: Nutrition Knowledge and Parent-Child Interactions. The current study is an ongoing, multi-site, clinical trial examining two innovative approaches to diet education. One treatment, Nutrition Education (NE), addresses the issue of lack of dietary knowledge by providing families an intensive 7-session program of nutritional suggestions for meeting the CF RDA for energy on a meal-by-meal basis. This intervention differs from the standard of care nutritional support typically offered by CF Centers in its intensity (weekly meetings) and specificity (individualized sessions on a meal-by-meal basis). The second intervention, Behavior Education (BE), combines the nutrition education component plus training on behavioral child management skills, such as contingent attention to appropriate eating, ignoring behaviors incompatible with eating, and use of contingent privileges for meeting calorie goals. To date, 33 children at the 3 centers (Cincinnati, Rhode Island, and Indiana) between ages 4 and 12 years have completed treatment and 26 of these have completed the 6 month followup. At baseline, the two groups were equivalent on weight (BE mean = 21.1 kg; NE mean = 21.2 kg) and calorie intake (BE mean = 1856 ca/day; NE mean = 1770 cal/day). At post-treatment (9 weeks), the children in the BE groups demonstrated a significantly greater increase in caloric intake than the children in the NE group. The BE group also showed a significantly greater weight gain compared to the NE group. At the 6-month followup, both groups demonstrated a similar rate of weight gain from post-treatment. The BE group gained an average of 0.98 kg, bringing their total weight gain pre-treatment to 6 months post-treatment to 2.66 kg. The NE group gained an average of 0.87 kg post-treatment to 6 month followup, with a total weight gain of 1.61 kg pre-treatment to 6 months post-treatment. Differences on weight gain post-treatment to 6 months and pre-treatment to 6 months were not significant between the two groups.